Signal device



Patented Mar. 3, 1942 SIGNAL DEVICE Irvin W. Cox, Milwaukee, Wis., assignor to Associated Electric Laboratories, Inc., Chicago, 111., a corporation of Delaware Application November 30, 1939, Serial No. 306,801

9 Claims. (Cl. 177-7) The present invention relates to signal devices and more particularly to ringers for use in telephone desk sets of the cradle typ or the like.

It is an object of the present invention to provide an improved signal device of the character described which is of rugged, compact and economical construction and which may readily be mounted directly within a telephone desk set of the cradle type.

It is a further object of the invention to provide an improved bell or ringer of the electromagnetically operated type wherein all of the parts of the striker operating mechanism are disposed entirely within the cavity of the signal Ong.

It is another object of the invention to provide in a signal device of the character described an improved striker mechanism of the electromagnetically operated type which is so compactly arranged that it may be mounted within the cavity of a relatively small signal gong.

It is still another objectof the invention to provide in a signal device of the character described an improved magnetic field structure which is so arranged that it may be easily assembled on a production basis, and, when assembled, is of such configuration and compact arrangement that it may easily be mounted entirely within the cavity of a relatively small signal gong.

The novel features believed to be characteristic of the invention are set forth with particularity in the appended claims. The invention, both as to its organization and method of operation, together with further objects and advantages thereof will best be understood by reference to the specification taken in connection with the accompanying drawing in which Figure 1 is an end elevational view of a signal device con structed and arranged in accordance with the present invention; Fig. 2 is a side view partially in section and taken along the line 2-2- of the device shown in Fig. 1; Figs. 3 and 4 are views illustrating the details of the electromagnetic field structure and the striker operating mechanism forminga part of the device shown in Fig. 1; Fig. 5 is an end view of the striker operating element embodied in the signal device shown in Fig. 1; and Fig. 6 illustrates the circuit wiring of the signal device shown in Fig. 1.

Referring now more particularly to Figs. 1 to 5,

inclusive, of the drawing, the signal device there illustrated comprises a substantially cup-shaped gong l0 having disposed within the cavity thereof a striker II in the form of a substantially U- shaped resilient member having resilient legs Ila and H17, respectively carrying striker heads or hammers In and I2b at points adjacent the free ends thereof. This member is nested within the cavity of the gong I0 so that the striker heads |2a and Nb are displaced slightly from diametrically opposed points of the interior Wall surface of the gong. For the purpose of operating the striker heads I27; and H17 alternately into engagement with the gong I0, there is Provided a non-magnetic operating element 13 which extends between the free ends of the legs Ma and Nb of a second substantially U-shaped resilient member l4 which is nested Within the first U- shaped resilient member ll so that the legs Ma and Nb thereof are substantially aligned with the legs Ila and Nb of the resilient member II. The U-shaped members II and i4 may be formed of fiat resilient non-magnetic stock having continuous surfaces, although, preferably, the element I4 is stamped as shown in Fig. 5 so that the legs Ma and [4b are sinuous in form. The respective ends of the element l3 extend through and are fabricated or otherwise secured to the sides of openings provided in the free extremities of the sinuous legs of the resilient member I4, an opening l4c being provided for receiving the right end of the elementl3. These openings are so disposed along. the legs Ma and lb that the ends of the element l3 are disposed in striking relationship with respect to the striker heads l2a and l2b carried by the legs of the resilient member H.

In order to impart reciprocating movement to the operating element l3, there is provided an electromagnetic operating mechanism which is also disposed entirely withinthe cavity of the gong II] and includes a magnetic field structure which comprises three substantially U-shaped field members l5, l6 and H. The two field members l6 and I! are of laminated structure and, preferably, the punched laminations thereof are formed of the magnetic material commercially known as Allegheny electric metal. The first field member 15 is permanently magnetized and is preferably formed of the magnetic material known commercially as Alnico. This material, as' is well known, is extremely hard and, accordingly, is not susceptible of machine tool operations such as drilling, punching, machining or the like. Accordingly, the U-shaped configuration is formed by casting this material, the molds being so constructed that parallel grooves are provided along the sides of the legs [5a and l5b of this member. These grooves, as formed in the leg I5a, receive a U-shaped assembly strap i8, the legs of which pass through registering openings punched through the base portion of the U-shaped field member I5 and similar registering openings provided in an assembly plate I9 disposed on the upper or outer surface of the field member IS. The ends of the legs of the U-shaped member I8 which project beyond the face of the assembly plate I9 are swedged over in order rigidly to mount the field member It on the end of the leg I502. In a similar manner the field member I1 is mounted on the end of the leg Ifib by providing a second substantially U-shaped assembly strap 2c, the legs of which straddle the leg I51) of the magnet I5, are disposed in the side grooves of this leg and pass through registering openings punched through the base of the field member I "I and also through registering openings provided in an assembly plate 2|. The ends of the legs of the assembly strap 20 which project beyond the face of the assembly plate 2| are also swedged over rigidly to secure the field member I! to the end of the magnet leg I5b. By

means of the mounting arrangement just de-.

scribed, the two field members I6 and I1 are so mounted upon the ends of the magnet legs 15a and I5!) that the legs thereof are disposed in substantially aligned relationship to provide two sets of separated pole faces. More particu larly, the arrangement is such that the legs Ifia and Ila are in alignment with each other and the end faces thereof are separated to provide north and south pole faces, respectively. Similarly, the legs I5?) and Ill) of the two field members I5 and Il, respectively, are disposed in sub-- stantial alignment and the end faces thereof are separated to provide north and south pole faces, respectively. These pole faces are beveled in the manner illustrated in Fig. 1 and each set is arranged to have disposed therebetween an armature piece which is carried by and ribidly mounted upon the striker operating element I3 in any suitable manner. More particularly, an armature piece 22a mounted upon the element I3 is disposed between the pole face ends of the two legs Ida and Ila, this armature piece normally occupying a position slightly out of alignment with the associated field legs and having its sides beveled to mate with the associated beveled pole face ends of the legs IBa and Ila, thereby to limit movement of the element I3 in one direction. In a similar manner a second armature piece 222), also mounted upon the element I3, is disposed between the pole face ends of the legs I61) and Ill) in a position slightly out of alignment with these legs, and is provided with beveled sides normally displaced from the pole face ends of the legs IBD and Ilb, but arranged to mate with these beveled pole face ends when drawn into alignment with the legs I61) and Ilb, thereby to limit movement of the element I3 in the other direction. The stiffness of the resilient U-shaped member I4 and, more particularly, the legs Ma and Idb thereof is such that the beveled sides of the armature pieces 22a and 22b are normally displaced from the associated pole faces by substantially equal distances. In order alternately to direct the predominant proportion of flux traversing the magnetic field structure through the field leg sets Ilia, Ila and IE1), Il'b, operating windings 23a, 24a, 23b and 24?) are respectively mounted upon these legs in any suitable manner, these windings being connected in series in the manner illustrated in Fig. 6.

The construction and arrangement of the elements thus far described is such that a single flanged assembly stud 25, formed of non-magnetic material, may be used for securing the various parts together in assembled relationship to provide a rigid assembly. More particularly, the base of the gong I0, the base of the resilient member I I, the base of the resilient member I4 and the base of the permanent magnet I5 are assembled in stacked relationship and are provided with registering openings therethrough, through which the shank of the flanged assembly stud 25 extends. Spacing washers 26 and 21, also formed of non-magnetic material, are respectively disposed between the elements II] and II, and the elements II and I4 so that movement of any one of these elements will not interfere with the movement of the associated elements. These spacing washers are also included in the assembly stack and are provided with openings adapted to receive the shank of the assembly stud 25. This assembly stud is provided with a lower threaded portion which receives a nut 25a so that when the nut is screwed into place against the outer surface of the gong III, the stacked elements are compressed between this nut and the flanged end of the stud 25 to provide a rigid assembly. Current is conducted to the operating windings 23a, 23b, 24a and 24b of the signal device over circuit conductors which are preferably brought out from the interior or cavity of the gong I0 through an opening 25b provided in the assembly stud 25. If desired, the threaded end of this stud may be extended for the purpose of utilizing the same to secure the signal device to any desired mounting structure.

Referring now more particularly to Fig. 6 of the drawing there is illustrated in schematic form an operating circuit for the signal device which comprises an alternating current source 29 and the normally open contacts 30 of a push button switch. With this arrangement and when the contacts 30 are moved into engagement, alternating current is caused to traverse the series connected windings of the signal device over obvious paths. These windings are so poled and are so connected that on one half of each cycle of the current traversing the same, the

flux traversing the legs Ilia and Ho of the magnetic field structure is decreased simultaneously with an increase in the flux traversing the legs I6?) and [lb of the field structure. Accordingly, the armature piece 22b is rapidly attracted into alignment with the legs Ifib and Ill) of the field structure so that the left end of the striker op erating element I3, as viewed in Fig. l, is moved with hammer-like rapidity into engagement with the leg II a of the resilient member II, thereby to bias this leg so that the striker head In is moved into engagement with the adjacent interior surface of the gong III. On each alternate half cycle of the supply current, the flux traversing the legs I BE) and [1b of the field structure is decreased simultaneously with an increase in the flux traversing the legs I6a and Ho of this structure. Accordingly, the armature piece 22a is rapidly moved into alignment with its associated field legs Mia and Na so that the element I3, as viewed in Fig. l, is moved to the right to bring the right end thereof into engagement with the leg IIb of the resilient member II, thereby to bias this leg so that the striker head I2!) is moved into engagement with the adjacent interior surface of the gong I0. Thus,

by virtue of the reciprocating movement of the element l3 which occurs when the windings 23a, 23b, 24a and 24b are energized with alternating current of a suitable frequency, the striker heads in and Nb are alternately driven into engagement with the interior surface of the gong I0.

While there has been described what is at present considered to be the preferred embodiment of the invention, it will be understood that various modifications may be made therein, and it is contemplated to cover in the appended claims all such modifications as fall within the true spirit and scope of the invention.

What is claimed is:

1. A signal device comprising a substantially cup-shaped gong, a striker comprising a substantially U-shaped member nested within said gong and provided with resilient legs each carrying a striker head, and electromagnetic means for actuating said legs to move said striker heads into engagement with said gong.

2. A signal device comprising a substantially cup-shaped gong, a striker comprising a pair of resiliently mounted striking heads, and striker operating means comprising a substantially U-shaped member nested within said gong and provided with resilient legs and an element extending between and supported by said legs so that the ends thereof are disposed in striking relationship with said striker heads.

3. A signal device comprising a substantially cup-shaped gong, a striker comprising a substantially U-shaped member nested within said gong and provided with resilient legs each carrying a striker head, a second substantially U-shaped member nested within said first-named U-shaped member and provided with resilient legs disposed substantially in alignment with the legs of said first-named U-shaped member, an element extending between and supported by th legs of said second U-shaped member, and electromagnetic means for imparting reciprocating movement to said element, thereby to cause said striker heads alternately to be moved into enagement with said gong.

4. A signal device comprising a substantially cup-shaped gong, a striker comprising a substantially U-shaped member nested within said gong and provided with resilient legs each carrying a striker head, a second substantially U- shaped member nested within said first-named U-shaped member and provided with resilient legs disposed substantially in alignment with the legs of said first-named U-shaped member, an

element extending between and supported by the 7 legs of said second U-shaped member, electromagnetic means including a field structure and an armature piece carried by said element and operative to impart reciprocating movement to said element, thereby to cause said striker heads alternately to be moved into engagement with said gong, and means supporting said field structure and said U-shaped members in assembled relationship within the cavity of said gong.

5. A signal device comprising a substantially cup-shaped gong, a striker comprising a substantially U-shaped member nested within said gong and provided with resilient legs each carrying a striker head, a second substantially U- shaped member nested within said first-named U-shaped member and provided with resilient legs disposed substantially in alignment with the legs of said first-named U-shaped member, an element extending between and supported by the egs of said second U-shaped member, a magnetic field structure comprising a first U-shaped magnet member and a pair of other U-shaped field members mounted upon the legs of said first magnet member so that the legs of said other field members extend toward each other in substantially aligned relationship to provide two sets of separated pole faces, operating windings carried by the legs of said other field members, and armature pieces carried by said element and respectively disposed between said sets of pole faces but normally slightly out of alignment with the respectiveassociated legs of said other field members, whereby said element is reciprocated to move said striker heads alternately into engagement with said gong when said windings are energized.

6. A signal device comprising a substantially cup-shaped gong, a striker comprising a substantially U-shaped member nested within said gong and provided with resilient legs each carrying a striker head, a second substantially U- shaped member nested within said first-named U-shaped member and provided with resilient legs disposed substantially in alignment with the legs of said first-named U-shaped member, an element extending between and supported by the legs of said second U-shaped member, a magnetic field structure comprising a first U-shaped magnet member and a pair of other U-shaped field members mounted upon the legs of said first magnet member so that the legs of said other field members extend toward each other in substantially aligned relationship to provide two sets of separated pole faces, operating windings carried by the legs of said other field members, armature pieces carried by said element and respectively disposed between said sets of pole faces but normally slightly out of alignment with the respective associated legs of said other field members, whereby said element is reciprocated to move said striker heads alternately into engagement with said gong when said windings are energized, said U-shaped resilient members and said first magnet member being assembled in stacked relationship within the cavity of said gong, and means comprising a single stud extending through said gong and said stacked members for rigidly securing said stacked members together.

7. A signal device comprising a gong, a gong striker, a magnetic field structure comprising a first U-shaped magnet member and a pair of other U-shaped field members mounted upon the legs of said first magnet member so that the legs of said other field members extend toward each other in substantially aligned relationship to provide two sets of separated pole faces, operating windings carried by the legs of said other field members, and a striker operating member supported for reciprocating movement between said pole faces and carrying armature pieces respectively extending between said sets of pole faces but normally slightly out of alignment with the respective associated legs of said other field members.

8. A signal device comprising a gong, a gong striker, a magnetic field structure comprising a first U-shaped magnet member and a pair of other U-shaped field members mounted upon the legs of said first magnet member so that the legs of said other field members extend toward each other in substantially aligned relationship to provide two sets of separated pole faces, operating windings carried by the legs of said other field members, a substantially U-shaped member having resilient legs disposed substantially in alignment with the transverse axis of said pole faces, and a striker operating member supported by said resilient legs for reciprocating movement between said pole faces and carrying armature pieces respectively extending between said sets of pole faces but normally slightly out of alignment with the respective associated legs of said other field members.

9. A signal device comprising a gong, a gong striker, a magnetic field structure comprising a first U-shaped magnet member and a pair of other U-shaped field members mounted upon the legs of said first magnet member so that the legs of said other field members extend toward each other in substantially aligned relationship to provide two sets of separated pole faces, operating windings carried by the legs of said other field members, a substantially U-shaped memher having resilient legs disposed substantially in alignment with the transverse axis of said pole faces, a striker operating member supported by said resilient legs for reciprocating movement between said pole faces and carrying armature pieces respectively extending between said sets of pole faces but normally slightly out of alignment with the respective associated legs of said other field members, and means supporting said field structure and said U-shaped member in assembled relationship within the cavity of said IRVIN W. COX. 

